Surfactant composition and use thereof

ABSTRACT

A surfactant composition comprising (a) a sulfosuccinate based compound; and (b) a C 16 -C 22  alkyl sulfate or an alkyl ether sulfate containing C 16 -C 22  alkyl is provided. A solid agrochemical composition containing said surfactant composition and the use thereof is also provided.

TECHNICAL FIELD

The present invention relates to a surfactant composition. Thesurfactant composition can notably be used as a low foaming wettingagent for solid agrochemical formulations. The surfactant compositioncomprises a sulfosuccinate based compound, and a C₁₆-C₂₂ alkyl sulfateor an alkyl ether sulfate containing C₁₆-C₂₂ alkyl.

BACKGROUND

An agrochemical formulation is generally a homogeneous and stablemixture of active ingredients and inert ingredients which make the finalproduct simpler, safer, and more efficacious to apply to a target pest.Active ingredients used in agrochemical formulations can be prepared anddelivered in various forms, such as powders, granules, emulsions anddispersions. Accordingly, the agrochemical formulations may be in theform of sprayable solid, sprayable liquid, sprayable granule, etc.

One type of agrochemical formulations can be in a water dispersiblesolid form, which may be sprayed for agricultural treatments afterdilution. In particular, such formulations include water dispersiblegranules (WDG), dry flowable (DF) and wettable powders (WP) of a solidactive ingredient or a liquid active ingredient loaded onto a solidcarrier, which can effect WDG, DF and WP formulations. Some activeingredients that are ultimately soluble in a final dilution useful forspraying may require initial dispersion in water for dissolution to takeeffect. These particular examples of WDGs may be alternatively describedas water soluble granules (WSG).

A further type of agrochemical formulation is a stable suspension ofsolid active ingredient(s) in a fluid usually intended for dilution withwater before use. Such formulations typically include the suspensionconcentrate (SC) and suspoemulsion (SE) formulation type.

Still a further type of agrochemical formulation is to deliver solidactive ingredient(s) on inert or fertilizer carriers. Such formulationsare typically prepared as granules to be applied to soils and arereferred to as slow dispersing granule (GR) formulations.

In these formulations, the solid active ingredient or the liquid activeingredient loaded on the solid carrier generally requires beingdispersed fully back to its primary particle size, or remaining fullydispersed, such that the formulation thereafter maintains a stabledispersion that is suitable for spraying. Also, it is desired that theformulation has good wetting capacities. In order to enhance dispersionand wetting of the formulation, as well as many other benefits,surfactants are usually added into agrochemical formulations forimproving the performance.

One problem associated with agrochemical formulations that are based onactive ingredients in solid dispersible form or a pre-dispersed form isdevelopment of foaming during the dispersion and dilution processes.Foaming may be generated when the formulations are agitated. Suchfoaming can lead to difficulties in the even spraying of the sprayliquid. Further difficulties include a foam-over or spillage of thespray liquid from out of the top of the mixing vessel. In addition, thedevelopment of foam may require a farmer to wait a long time for thefoam to subside before spraying or may require the addition of defoamingagents which may be expensive, such as those based on silicone oilemulsions.

Surfactants in agrochemical formulations can be the major source of thefoaming. For example, alkyl sulfate and alkyl ether sulfate are known aswetting agents for agrochemical formulations. However, alkyl sulfatecould cause significant foaming. PCT international patent publicationno. 2014/172469 discloses use of alkyl sulfate and alkyl ether sulfatein a foaming agent composition.

Various attempts have been made to provide low foaming WP and WDGagrochemical formulations. It is disclosed that alcohol alkoxylates canbe used as low foaming wetting agents. However, the resultingformulations exhibited poor dispersion performance. Fatty acid salts aredisclosed to reduce foaming. However, the foam reduction capacity offatty acid salts is not satisfactory.

There is a need to provide a surfactant composition having wettingcapacity which can reduce foaming in dispersion of agrochemicalformulations, such as WP and WDG. There is a need to provide a methodfor reducing or controlling foaming in the dispersion of agrochemicalformulations that are based on solid active ingredients. There is a needto provide a solid agrochemical formulation which provides low foamingcombined with good wetting capacities.

SUMMARY OF INVENTION

In one aspect, the present invention provides a surfactant compositionwhich comprises:

(a) a sulfosuccinate based compound; and(b) a C₁₆-C₂₂ alkyl sulfate or an alkyl ether sulfate containing C₁₆-C₂₂alkyl.

Said surfactant composition is notably a surfactant composition used fora solid agrochemical composition.

Without wishing to be bound by theory, the surfactant composition of theinvention provides a combination of foaming reduction and wettingcapacities. It has been surprisingly found that agrochemicalformulations incorporating the surfactant composition exhibited reducedfoaming when they are dispersed. Foaming of the formulations could bereadily measured by standard foaming tests known by a skilled person.Also, the surfactant composition could provide the formulations withexcellent wetting capacities.

The term “solid agrochemical composition”, as used herein, means anagrochemical formulation which contains a solid agriculturally activeingredient per se, or a solid/liquid agriculturally active ingredientthat is formulated into a solid form. The solid agrochemical compositionincludes water dispersible granule (WDG), dry flowable (DF), wettablepowder (WP), suspension concentrate (SC), suspoemulsion (SE), slowdispersing granule (GR), and water soluble granule (WSG) formulationsand any other solid dispersible formulation types as may be classifiedfrom time to time by the Crop Life International organization. It isappreciated that the solid agrochemical composition includes dispersionand/or dilution of agrochemical formulations that are based on solidactive ingredient(s).

In another aspect, the present invention provides a solid agrochemicalcomposition comprising said surfactant composition and an agriculturallyactive ingredient. Accordingly, the solid agrochemical compositioncomprises:

(a) an agriculturally active ingredient, notably in solid form;(b) a sulfosuccinate based compound; and(c) a C₁₆-C₂₂ alkyl sulfate or an alkyl ether sulfate containing C₁₆-C₂₂alkyl.

In still another aspect, the present invention provides a method forreducing or controlling the foaming of a solid agrochemical composition,wherein the method comprises the step of adding to the composition asurfactant composition comprising:

(a) a sulfosuccinate based compound; and(b) a C₁₆-C₂₂ alkyl sulfate or an alkyl ether sulfate containing C₁₆-C₂₂alkyl.

DETAILED DESCRIPTION

Throughout the description, including the claims, the term “comprisingone” or “comprising a” should be understood as being synonymous with theterm “comprising at least one”, unless otherwise specified. The terms“between” and “from . . . to . . . ” should be understood as beinginclusive of the limits.

The articles “a”, “an” and “the” are used to refer to one or to morethan one (i.e., to at least one) of the grammatical object of thearticle.

It should be noted that in specifying any range of concentration, weightratio or amount, any particular upper concentration, weight ratio oramount can be associated with any particular lower concentration, weightratio or amount, respectively.

As used herein, the term “alkyl” means a saturated hydrocarbon radical,which may be straight, branched or cyclic, such as, methyl, ethyl,n-propyl, iso-propyl, n-butyl, sec-butyl, t-butyl, pentyl, n-hexyl,cyclohexyl.

As used herein, the term “alkenyl” as a group or part of a group denotesan aliphatic hydrocarbon group containing at least one carbon-carbondouble bond and which may be straight or branched. The group may containa plurality of double bonds in the normal chain and the orientationabout each is independently E or Z. Exemplary alkenyl groups include,but are not limited to, ethenyl, propenyl, butenyl, pentenyl, hexenyl,heptenyl, octenyl and nonenyl. The group may be a terminal group or abridging group.

As used herein, the term “hydroxyalkyl” means an alkyl radical, which issubstituted with a hydroxyl groups, such as hydroxymethyl, hydroxyethyl,hydroxypropyl, and hydroxydecyl.

As used herein, the terminology “(C_(n)-C_(m))” in reference to anorganic group, wherein n and m are each integers, indicates that thegroup may contain from n carbon atoms to m carbon atoms per group.

As used herein, the term “agriculturally acceptable salts” refers tosalts prepared from agriculturally acceptable non-toxic bases or acidsincluding inorganic or organic bases and inorganic or organic acids.Typical agriculturally acceptable salts referred to herein comprise ananion derived from the compound, for example, by deprotonation of ahydroxy or hydroxyalkyl substituent, and one or more positively chargedcounterions. Suitable positively charged counterions include inorganiccations and organic cations, such as for example, sodium cations,potassium cations, calcium cations, magnesium cations, isopropylaminecations, ammonium cations, and tetraalkylammonium cations.

As used herein, “C₁₆-C₂₂ alkyl sulfate” refers to an alkyl sulfate whichcontains C₁₆-C₂₂ alkyl chain(s) only or an alkyl sulfate which containssubstantially C₁₆-C₂₂ alkyl chains. An alkyl sulfate which containssubstantially C₁₆-C₂₂ alkyl chains means an alkyl sulfate which containsa mixture of C₁₆-C₂₂ alkyl chain(s) as well as shorter alkyl chain(s),wherein content of the C₁₆-C₂₂ alkyl chain(s) is at least 90 wt % of thetotal alkyl chains. As used herein, “C₁-C₁₄ alkyl sulfate” refers to analkyl sulfate which contains C₁-C₁₄ alkyl chain(s) only or an alkylsulfate which contains substantially C₁-C₁₄ alkyl chains. An alkylsulfate which contains substantially C₁-C₁₄ alkyl chains means an alkylsulfate which contains a mixture of C₁-C₁₄ alkyl chain(s) as well aslonger alkyl chain(s), wherein content of the C₁-C₁₄ alkyl chain(s) isat least 90 wt % of the total alkyl chains. It should be understood inthe same way when referring to alkyl chain length in alkyl ethersulfates.

The surfactant composition of the present invention comprises (a) asulfosuccinate based compound; and (b) a C₁₆-C₂₂ alkyl sulfate or analkyl ether sulfate containing C₁₆-C₂₂ alkyl. Preferably, component (b)is a C₁₆-C₂₂ alkyl sulfate.

The sulfosuccinate based compound include agriculturally acceptablesalts of mono-esters of sulfosuccinic acid, agriculturally acceptablesalts of di-esters of sulfosuccinic acid, each of which may optionallybe alkoxylated, as well as mixtures thereof.

Examples of the sulfosuccinate based compound include and are notlimited to:

disodium monooctylsulfosuccinate, disodium lauryl sulfosuccinate,disodium isodecyl sulfosuccinate, disodium tridecyl sulfosuccinate,diammonium lauryl sulfosuccinate, disodium laureth sulfosuccinate,disodium decyl-PEG-4 sulfosuccinate, disodium laureth-5 sulfosuccinate,disodium laurimide (MEA) sulfosuccinate, disodium cocamide MIPAsulfosuccinate, disodium oleamido MIPA sulfosuccinate, disodiumoleylamido PEG-2 sulfosuccinate, disodium cocamido MEA sulfosuccinate,diammonium lauramido MEA sulfosuccinate, sodium dioctyl sulfosuccinate,sodium bistridecyl sulfosuccinate, sodium dihexyl sulfosuccinate, sodiumdicyclohexyl sulfosuccinate, sodium diamyl sulfosuccinate, sodiumdiisobutyl sulfosuccinate.

Preferably, the sulfosuccinate based compound is according to thegeneral formula (I):

wherein:R₁ and R₂, same or different, is

wherein R₃ is H, C₁-C₄ alkyl, alkenyl, hydroxyalkyl or hydroxyalkenyl,such as methyl, ethyl, propyl, iso-propyl, butyl, and iso-butyl,preferably R₃ is H or methyl;R₄ is C₁-C₂₂ alkyl, alkenyl, hydroxyalkyl or hydroxyalkenyl, preferablyC₁-C₁₆ alkyl, alkenyl, hydroxyalkyl or hydroxyalkenyl, more preferablyC₄-C₁₆ alkyl, alkenyl, hydroxyalkyl or hydroxyalkenyl, still morepreferably C₈-C₁₆ alkyl or hydroxyalkyl;n is 0 or an integer of 1 to 100, preferably 0 or an integer of 1 to 50,more preferably 0 or an integer of 1 to 30, in particular, n is aninteger of 1 to 30; X⁺ is H or a cation, for example, NH₄, an alkalimetal such as sodium, potassium and calcium, an alkyl substitutedammonium such as ethylamine, propylamine and isopropylamine, and ahydroxyalkyl substituted ammonium such as alkanolamine.

More preferably, the sulfosuccinate based compound is according to thegeneral formula (I):

wherein:R₁ and R₂, same or different, is R₄—O—, wherein R₄ is C₁-C₂₂ alkyl,alkenyl, hydroxyalkyl or hydroxyalkenyl, preferably C₁-C₁₆ alkyl,alkenyl, hydroxyalkyl or hydroxyalkenyl, more preferably C₄-C₁₆ alkyl,alkenyl, hydroxyalkyl or hydroxyalkenyl, still more preferably C₈-C₁₆alkyl or hydroxyalkyl;X⁺ is H or a cation, for example, NH₄, an alkali metal such as sodium,potassium and calcium, an alkyl substituted ammonium such as ethylamine,propylamine and isopropylamine, and a hydroxyalkyl substituted ammoniumsuch as alkanolamine.

Further examples of the sulfosuccinate based compound include Aerosol®series (Solvay), the Agrilan® or Lankropol® series (Akzo Nobel), theEmpimin® series (Albright & Wilson), the Cropol® series (Croda), theLutensit® series (BASF), the Triton® series (Union Carbide), theGeropon® series (Solvay), the Imbirol®, Madeol® or Polirol® series(Cesalpinia).

The C₁₆-C₂₂ alkyl sulfate suitable for the present invention may be alinear alkyl sulfate or a branched alkyl sulfate. The C₁₆-C₂₂ alkylsulfate may be a primary alkyl sulfate or a secondary alkyl sulfate. Inthe cases of branched alkyl sulfates, the C₁₆-C₂₂ alkyl sulfate maycomprise one, two or more branches. The C₁₆-C₂₂ alkyl sulfate may be ablend of alkyl sulfates having different alkyl chain lengths and may bea blend of linear and branched alkyl sulfates.

The C₁₈-C₂₂ alkyl sulfate includes:

1. primary akyl sulfates derived from alcohols made by Oxo reaction onpropylene or n-butylene oligomers;2. primary alkyl sulfates derived from oleic-containing lipids;3. primary alkyl sulfates, for example the so-called “tridecyl” typesderived from oligomerizing propylene with an acid catalyst followed byOxo reaction;4. primary alkyl sulfates derived from “Neodol” or “Dobanol” processalcohols: these are Oxo products of linear internal olefins or are Oxoproducts of linear alpha-olefins. The olefins are derived by ethyleneoligomerization to form alpha-olefins which are used directly or areisomerized to internal olefins and metathesized to give internal olefinsof differering chain-lengths;5. primary alkyl sulfates derived from the use of “Neodol” or “Dobanol”type catalysts on internal olefins derived from feedstocks which differfrom those normally used to make “Neodol” or “Dobanol” alcohols, theinternal olefins being derived from dehydrogenation of paraffins frompetroleum;6. primary alkyl sulfates derived from conventional (e.g.,high-pressure, cobalt-catalyzed) Oxo reaction on internal olefins, theinternal olefins being derived from dehydrogenation of paraffins frompetroleum;7. primary alkyl sulfates derived from conventional (e.g.,high-pressure, cobalt-catalyzed) Oxo reaction on alpha-olefins;8. primary alkyl sulfates derived from natural linear fatty alcoholssuch as those commercially available from Procter & Gamble Co.;9. primary alkyl sulfates derived from Ziegler alcohols such as thosecommercially available from Albermarle;10. primary alkyl sulfates derived from reaction of normal alcohols witha Guerbet catalyst (the function of this well-known catalyst is todehydrogenate two moles of normal alcohol to the corresponding aldehyde,condense them in an aldol condensation, and dehydrate the product whichis an alpha, beta-unsaturated aldehyde which is then hydrogenated to the2-alkyl branched primary alcohol, all in one reaction “pot”);11. primary alkyl sulfates derived from dimerization of isobutylene toform 2,4,4′-trimethyl-1-pentene which on Oxo reaction to the aldehyde,aldol dimerization, dehydration and reduction gives alcohols;12. secondary alkyl sulfates derived from sulfuric acid addition toalpha- or internal-olefins;13. primary alkyl sulfates derived from oxidation of paraffins by stepsof (a) oxidizing the paraffin to form a fatty carboxylic acid; and (b)reducing the carboxylic acid to the corresponding primary alcohol;14. secondary alkyl sulfates derived from direct oxidation of paraffinsto form secondary alcohols;15. Primary or secondary alkyl sulfates derived from various plasticizeralcohols, typically by Oxo reaction on an olefin, aldol condensation,dehydration and hydrogenation (examples of suitable Oxo catalysts arethe conventional Co, or more recently, Rh catalysts); and16. primary or Secondary alkyl sulfates other than of linear primarytype, for example phytol, farnesol, isolated from natural productsources.

Preferably, the C₁₆-C₂₂ alkyl sulfate is represented by the generalformula (II):

R₅OSO₃ ⁻M⁺  (II)

wherein R₅ is a C₁₆-C₂₂ alkyl or hydroxyalkyl group, either linear orbranched, M⁺ is a cation, such as sodium, potassium, magnesium,ammonium, and organic derivatives thereof, such as monoethanolamine,diethanolamine or triethanolamine. In some preferred embodiments, M⁺ issodium or ammonium.

Further examples of the C₁₆-C₂₂ alkyl sulfate include Lanette® E andKollliphor® CSS (from BASF).

The alkyl ether sulfate containing C₁₆-C₂₂ alkyl may be represented bythe general formula (III):

R₆(AO)_(n)OSO₃ ⁻M⁺  (III)

wherein R₆ is a C₁₆-C₂₂ alkyl or hydroxyalkyl group, either linear orbranched;AO is ethylene oxide (EO), propylene oxide (PO) or mixture thereof,preferably ethylene oxide;n represents degree of alkoxylation, n may be an integer of 1 to 100,preferably n is an integer of 1 to 30, more preferably 1 to 10;M⁺ is a cation, such as sodium, potassium, magnesium, ammonium, andorganic derivatives thereof, such as monoethanolamine, diethanolamine ortriethanolamine. In some preferred embodiments, M⁺ is sodium orammonium.

Examples of the alkyl ether sulfate containing C₁₆-C₂₂ alkyl includesodium cetostearyl ether sulfate, sodium cetyl ether sulfate, sodiumstearyl ether sulfate, such as ALFOTERRA® series from Sasol.

In a preferred embodiment, said surfactant composition further containsa C₁-C₁₄ alkyl sulfate or an alkyl ether sulfate containing C₁-C₁₄alkyl.

According, the present invention also relates to a surfactantcomposition which comprises (a) a sulfosuccinate based compound; (b) aC₁₆-C₂₂ alkyl sulfate or an alkyl ether sulfate containing C₁₆-C₂₂alkyl; and (c) a C₁-C₁₄ alkyl sulfate or an alkyl ether sulfatecontaining C₁-C₁₄ alkyl. Preferably, component (b) is at least 5 wt % of(b) and (c), such as 5 wt % to 99 wt % of (b) and (c). More preferably,component (b) is at least 8 wt % of (b) and (c), such as 8 wt % to 99 wt% of (b) and (c). Still more preferably, component (b) is at least 10 wt% of (b) and (c), such as 10 wt % to 99 wt % of (b) and (c).

In some embodiments, said C₁₆-C₂₂ alkyl sulfate or alkyl ether sulfateis branched. In some embodiments, said C₁-C₁₄ alkyl sulfate or alkylether sulfate is branched. In some embodiments, both the C₁₆-C₂₂ alkylsulfate or alkyl ether sulfate component and the C₁-C₁₄ alkyl sulfatesor alkyl ether sulfate component are branched.

Examples of branched C₁₆-C₂₂ alkyl sulfate include sodium heptadecylsulfate, sodium iso-hexadecyl sulfate. Examples of branched C₁-C₁₄ alkylsulfate include sodium isotridecyl sulfate, sodium isodecyl sulphate.

The surfactant composition may be provided as a discrete composition foruse in dispersing an active ingredient in solid form, such as formulatedinto a WDG, SC or WP, or alternatively simply formulated together withthe active ingredient.

The surfactant composition preferably contains the sulfosuccinate basedcompound in an amount of from 1% to 50%, more preferably from 1% to 35%,based on total weight of the surfactant composition.

The surfactant composition preferably contains the C₁₆-C₂₂ alkyl sulfateor the alkyl ether sulfate containing C₁₆-C₂₂ alkyl, in an amount offrom 1% to 90%. In some embodiments, said amount is from 5% to 35%,based on total weight of the surfactant composition. In someembodiments, said amount is from 70 to 90%, based on total weight of thesurfactant composition.

In another aspect of the present invention, there is provided a solidagrochemical composition comprising: (a) an agriculturally activeingredient; (b) a sulfosuccinate based compound; and (c) a C₁₆-C₂₂ alkylsulfate or an alkyl ether sulfate containing C₁₆-C₂₂ alkyl. Inparticular, there is provided a solid agrochemical compositioncomprising (a) an agriculturally active ingredient; (b) a sulfosuccinatebased compound; (c) a C₁₆-C₂₂ alkyl sulfate or an alkyl ether sulfatecontaining C₁₆-C₂₂ alkyl; and (d) a C₁-C₁₄ alkyl sulfate or an alkylether sulfate containing C₁-C₁₄ alkyl.

The agriculturally active ingredient is notably an active ingredient insolid form, either the active ingredient per se is solid, or the activeingredient is a solid or liquid which is provided in solid form, forexample, loaded on a solid carrier.

The agriculturally active ingredient include any chemical substance thatadversely effects the longevity, reproductive capability, and/or growthor metabolic function of plants, insects, fungi, and/or other variousphyla. In particular, the agriculturally active ingredient is one ormore selected from a herbicide, an insecticide, a fungicide, anacaricide, and a rodenticide.

The agriculturally active ingredient includes without limitationherbicides (e.g., triazines, ureas and sulphonyl ureas), insecticides(e.g., imidacloprid, fipronil and synthetic pyrethroids), fungicides,biocides, molluscicides, algaicides, plant growth regulators,anthelmintics, rodenticides, nematocides, acaricides, amoebicides,protozoacides, crop safeners, adjuvants, or combinations thereof.Without limitation, examples of the agriculturally active ingredients ingranulated or powder form in agricultural applications include triazineherbicides such as simazine, atrazine, terbuthylazine, terbutryn,prometryn and ametryn; urea herbicides such as diuron and fluometron;sulphonyl urea herbicides such as chlorsulfuron, metsulfuron methyl,nicosulfuron and triasulfuron; sulphonanilide herbicides such asflumetsulam; organophosphate insecticides such as azinphos methyl,chlorpyrifos, sulprofos and azamethiphos; carbamate insecticides such asaldicarb, bendiocarb, carbaryl and fenobucarb (2-sec-butylphenylmethylcarbamate); synthetic pyrethroids such as bifenthrin; fungicidesincluding chlorothalonil, dimethomorph, benomyl, carbendazim, mancozeb;triazoles such as hexaconazole and diniconazole; and acaricides such aspropargite.

In some embodiments, the agriculturally active ingredient is a triazinesuch as atrazine and simazine. In some embodiments, the agriculturallyactive ingredient is a triazine, urea, or combination thereof in a WDGor WP formulation. It is appreciated that the compositions may includeone or more than one agriculturally active ingredient.

The solid agrochemical composition may comprise the surfactantcomposition, which contains the sulfosuccinate based compound and thealkyl sulfate/alkyl ether sulfate described herein, in an amount of from0.1% to 10%, preferably from 0.5% to 5%, based on total weight of thesolid agrochemical composition.

The surfactant composition or the agrochemical composition according tothe present invention may further comprise other agriculturally suitableingredients/excipients, such as solvents, pH modifiers, crystallizationinhibitors, viscosity modifiers, suspending agents, spray dropletmodifiers, pigments, antioxidants, light-blocking agents,compatibilizing agents, antifoam agents/antifoamers, sequesteringagents, neutralizing agents, corrosion inhibitors, dyes, odorants,spreading agents, penetration aids, emolients, lubricants, stickingagents, dispersing agents/dispersants, thickening agents, freezing pointdepressants, antimicrobial agents, and insect repellants.

The surfactant composition or the agrochemical composition may comprisean additional wetting agent. The additional wetting agents arepreferably alkylpolysaccharides, alcohol ethoxylates and alkylphenolethoxylates. Since many of these are in liquid form, they are oftenprovided in a solid form by incorporation into a solid matrix.Non-limiting examples from the alkylpolysaccharide class of wettingagents are alkylpolyglucosides derived from reaction with glucose and aprimary hydrocarbon alcohol. Examples of the additional wetting agentthat can be used include APG® 325, PLANTAREN® 2000, PLANTARN® 1300,AGRIMUL® PG 2067 (all from Cognis Corporation), ATPLUS® 438 and ATPLUS®452 (from Uniqema, Inc.). In some embodiments, the surfactantcomposition or the agrochemical composition further comprises analkylpolysaccharide as the additional wetting agent, such as analkylpolyglycoside (APG).

The surfactant composition or the agrochemical composition may furthercomprise a fatty acid salt. The fatty acid salt suitable for theinvention may include any fatty acid suitable for use with anagriculturally active ingredient. In one embodiment, the fatty acid saltis a salt of a C₈ to C₂₂ fatty acid, which may be saturated orunsaturated (e.g., one of more degrees of unsaturation such as cisand/or trans). Without limitation, examples of saturated fatty acidsinclude C₁₂ (lauric acid), C₁₄ (myristic acid), C₁₆ (palmitic acid), andC₁₈ (stearic acid). Without limitation, examples of unsaturated fattyacids include C₁₈ (oleic acid and elaidic acid). The fatty acid saltsmay include any suitable salts. Without limitation, examples of suitablesalts include ammonium and alkyl amine salts (e.g. NH₄ ⁺, NHEt₃ ⁺),alkali metal (e.g. Li⁺, Na⁺, K⁺) and alkaline earth (e.g. Mg²⁺ and Ca²⁺)salts, and trivalent metal salts (e.g. Al³⁺). Without limitation,examples of suitable fatty acid salts include sodium stearate, sodiumoleate, aluminum stearate, or combinations thereof.

The surfactant composition or the agrochemical composition may furthercomprise defoamers. Suitable defoamers include all customary defoamers,preferably silicone-based defoamers, such as silicone oils, for example.Preferred defoamers are those from the group of linearpolydimethylsiloxanes having an average dynamic viscosity, measured at25° C., in the range from 1000 to 8000 mPas, preferably 1200 to 6000mPas, and containing silica. Silica comprehends forms/modifications suchas polysilicic acids, meta-silicic acid, ortho-silicic acid, silica gel,silicic acid gels, kieselguhr, precipitated S_(i)O₂, etc. Defoamers fromthe group of linear polydimethylsiloxanes contain as their chemicalbackbone a compound of the formula HO—[S_(i)(CH₃)₂—O—]_(n)—H, in whichthe end groups are modified, by etherification for example, or, ingeneral, are attached to the groups —S_(i)(OH₃)₃. The amount of silicacan be modified within a wide range and is generally situated in therange from 0.1 to 10 percent by weight, preferably 0.2 to 5 percent byweight, in particular 0.2% to 2% by weight, of silica, based on theweight of polydimethylsiloxane. Examples of defoamers of this kind areRhodorsil® Antifoam 416 and Rhodorsil® Antifoam 481 (Solvay). Furtherdefoamers from the silicone group are Rhodorsil® 1824 (Solvay),Antimussol® 4459-2 (Clariant), Defoamer V 4459 (Clariant), SE Visk andAS EM SE 39 (Wacker).

The surfactant composition or the agrochemical composition may furtherinclude surfactants as dispersing agents, which include but are notlimited to salts of alkylphenol condensates, salts of sulphonatedlignins, salts of poly acid resin copolymers, salts of polyphenolformaldehyde resins, salts of polyarylether sulphates such astristyrylphenolethoxylate sulphate salts, alkoxylated alkylphenols andalcohols as well as block copolymers of ethyleneoxide and propyleneoxide. Examples of dispersant that may be used include Geropon®Ultrasperse, Geropon® T/36, Geropon® SC/213, Geropon® TA/72, all fromSolvay, Atlox Metasperse 550S (Croda), and Tersperse® 2700 (Huntsman).

The surfactant composition or the agrochemical composition may alsoinclude other insoluble materials that may be used in agriculturalapplications such as fillers and carriers, for example, but not limitedto, natural and synthetic silicates and silicate minerals, mineraloxides and hydroxides and also natural and synthetically derived organicmaterials. Such materials may be added as porous carriers, as moistureinhibition agents, to aid binding or agglomeration properties of aformulation and/or to fill a formulation to a convenient weight.Examples of such fillers may include natural silicates such asdiatomaceous earth, synthetic precipitated silicas, clays such askaolin, attapulgites and bentonites, also zeolites, titanium dioxide,iron oxides and hydroxides, aluminium oxides and hydroxides, amorphousand crystalline silica, diatomite, talc, mica, urea-formaldehyde andpolyphenolic resins and calcium carbonate, ammonium sulphate, sodiumtripolyphosphate, calcium phosphate, urea and sodium carbonate ororganic materials such as bagasse, charcoal, or synthetic organicpolymers.

The solid agrochemical composition of the present invention may be WDG,DF, WP, SC, SE, GR, WSG formulations or any other solid dispersibleformulation types as may be classified from time to time by the CropLife International organization. For instance, the solid agrochemicalcomposition may be a suspension concentrate or suspoemulsion formulationtype (SC, SE) comprising water.

The solid agrochemical composition is usually dispersed in an aqueousmedium before use. Dispersion may be achieved by any suitable methods.For instance, the method may take into account the nature of thecomposition and compatibility with the components of the composition. Ina preferred embodiment, the dispersion of the composition in an aqueoussolution is conducted either by hand or with a minimum of mechanicalagitation. Mechanical agitation may include stirring, mixing, blendingand other suitable processes. The pH of the aqueous dispersion may befrom 2.0 to 10.0, preferably from 5.0 to 9.0.

The solid agrochemical composition can be prepared by mixing acombination of components including the surfactant composition describedherein, A “combination” of components, may refer to an intimate mixtureof components, optionally formulated together as a WDG, DF, WP, SC, SE,GR, or WSG, or merely placement of the respective components together ina dispersing or mixing vessel, or any other degree of admixture inbetween. Preparing an aqueous dispersion of the solid agrochemicalcomposition refers to providing and dispersing a combination, this caninclude providing all the components formulated together as a WDG, DF,WP, SC, SE, GR, or WSG, or the active ingredient formulated as a WDG,DF, WP, SC, SE, GR, or WSG, and the surfactant composition or part ofthe surfactant composition described herein is provided either asseparate components or as a “tank-mix” into the dispersing tank orvessel. Where at least one or more of the components are providedseparately, they can be optionally first mixed together beforedispersion, or alternatively, simply mixed during the dispersionprocess.

In still another aspect of the invention, there is provided a method forreducing or controlling the foaming of a solid agrochemical composition,comprising the step of adding to the agrochemical composition thesurfactant composition described herein. Foaming in dispersions of theagrochemical composition can be reduced by incorporating said surfactantcomposition in the agrochemical composition.

The solid agrochemical compositions according to the present inventionare especially suitable for use in crop protection wherein thecompositions are applied to the plants, to parts of the plants or to thearea under cultivation, such as to the soils in the area undercultivation.

EXAMPLES

Materials

Atrazine: 97% purity, from Hebei Shanli Chemical Co., Ltd;

Chlorothalonil: from Suli Co., Ltd.;

Simazine: from Zhejiang Zhongshan Chemical Industry Group Co., Ltd.;

Sulfosuccinate based compound (SS): sodium dioctylsulphosuccinate;

Alkyl sulfate (AS):

-   -   AS1: C₁₆-C₁₈ alkyl sulfate sodium salt, synthesized from natural        C₁₆-C₁₈ alcohol, C₁₆/C₁₈=29/71;    -   AS2: C₁₂-C₁₄ alkyl sulfate sodium salt;

Alkylpolysaccharide (AP): APG0810 from Yangzhou Chenhua New MaterialCo., Ltd.;

Dispersants: Geropon® Ultrasperse from Solvay;

Water C: CIPAC standard water, 500 ppm hardness;

Water D: CIPAC standard water, 342 ppm hardness.

Tests in Formulations Prepared by Liquid Mixing Method

The foaming reduction capacity of the inventive surfactant compositionwas tested by using formulations obtained by mixing the activeingredient, dispersant and wetting agent in water without a granulationprocess (liquid mixing method). This test enables quick and accurateevaluation of foaming and the results thereof have good consistency withresults obtained by the standard foaming test which is developed by theCollaborative International Pesticides Analytical Council (CIPAC) and isdescribed in Method MT 47.2, in which a granulation process is employed.

Firstly, the foaming of formulations that were prepared by the abovementioned liquid mixing method was tested in comparison with foaming ofgranule formulations which was measured according to the proceduredescribed in CIPAC Method MT 47.2. Results are shown in Table 1 below:

TABLE 1 #1 #2 #3 #4 Formulation Active Atrazine Dispersant Geropon ®Ultrasperse Wetting Agent Rodapon ® LS-94/WP Geropono ®L-WET/PFormulating Method Granule Liquid Granule Liquid Foaming (mm) 0″ 82 7876 62 1′ 82 78 16 10 3′ 54 78 2 6

Rodapon® LS-94/WP used in the above tests was a wetting agent which byitself caused high foaming while Geropon®L-WET/P was a wetting agentwhich cased comparatively low foaming. Results showed that the foamingtest results of formulations prepared by the liquid mixing method hadsubstantially similar trend with those of formulations prepared bystandard granular method, in both high and low foaming formulations.Such results demonstrated that the liquid mixing method can enableaccurate evaluation of foaming in agro formulations.

For tests of the foaming, Atrazine formulations were prepared by usingthe liquid mixing method and according to the recipe as below:

TABLE 2 Components Content (wt %; excluding filler) Atrazine (97%) 92.8%Dispersant  4.5% Surfactant Composition   2%

The formulations were prepared by the following procedures. The Atrazineactive ingredient was jet-milled before use, and then blended with thedispersant to form a powder mixture. The powder mixture was then dilutedwith Water D (CIPAC standard water, 342 ppm hardness) to form a 5 wt %(solid content) Solution A. Solution B was prepared by diluting thesurfactant composition with Water D to give a final solid content of 2.5wt %. Freshly prepared Solutions A and B were mixed in a cylinder forfoam assessment. Typically, 19.46 g of Solution A and 0.8 g of SolutionB were added in the cylinder, then topped up to 200 ml with Water D. Thecylinder was then inverted for 30 times. The cylinder was then holdupright and kept in a water bath of 30° C. Volume of the foams generatedin the formulations was measured and recorded at different time pointspost mixing, i.e. 0 sec, 1 min, and 3 mins.

The various surfactant compositions tested and the foaming test resultsare shown in Table 3 below:

TABLE 3 Surfactant Composition (wt %) Foam Volume (mm) # SS AS1 AS2 AP0″ 1′ 3′ EX1 10.0 90.0 — — 38 30 30 EX2 15.0 85.0 — — 40 8 0 EX3 30.070.0 — — 48 16 4 EX4 50.0 50.0 — — 46 8 2 EX5 70.0 30.0 — — 52 26 6 EX65.0 5.0 90.0 — 56 56 40 EX7 5.0 10.0 85.0 — 80 22 10 EX8 15.0 15.0 70.0— 72 28 16 CE1 — 100 — — 50 50 50 CE2 100 — — — 80 80 80 CE3 10 — 90 —86 86 86 CE4 15 — 85 — 88 88 88 CE5 20 — 80 — 86 86 86 CE6 — — 100 — 7878 78 CE7 25 — 55 20 72 72 72(“EX” means Example and “CE” means Comparative Example)

Results showed that the inventive surfactant compositions led tomarkedly reduced foaming compared to other surfactant compositionstested. The reduced foaming was indicated by reduced foaming volume inthe formulations post agitation.

Tests in WDG Formulations

In this set of experiments, WDG formulations were prepared andproperties of the formulations, including suspensibility, foaming anddisintegration, were tested.

WDG granules were prepared according to formulations shown in Table 4below:

TABLE 4 EX9 EX10 CE8 CE9 EX11 CE10 EX12 CE11 Formulation (wt %) Atrazine(97%) 92.8 92.8 92.8 92.8 — — — — Chlorothalonil — — — — 91.5 91.5 — —Simazine — — — — — — 92.8 92.8 Wetting agent 1 2 2 — — 2 — 2 — Wettingagent 2 — — 2 2 — 2 — 2 Dispersant 4.5 4.5 4.5 4.5 6 6 4 4 Kaolin 0.70.2 0.7 0.2 0.5 0.5 1.2 1.2 EDTA—2Na — 0.5 — 0.5 — — — — Total 100 100100 100 100 100 100 100 Wetting Agent 1 is the surfactant compositionaccording to Example 4. Wetting Agent 2 is the surfactant compositionaccording to Comparative Example 6.

The granules formulations were made by first milling the solid activeingredient, and then blending with the dispersant and the wetting agentpowder in a lab blender. A quantity of water approximately 20% (W/W) wasadded while the powder was mixed under agitation. The partly wet powderwas then extruded through a 1 mm screen on a laboratory scale baskettype extruder. The strands extruded were broken to approximately uniformsize by shaking and then dried to a residual water content ofapproximately 0.5% (W/W).

Foaming of the formulations was measured by following the procedure asdescribed above. Foaming at room temperature and 30° C. (1 min postagitation) was measured, respectively.

Suspensibility of the formulations was measured by following theprocedure described in CIPAC Method MT15. Generally, the granules (2.5g) were dissolved in Water C (CIPAC standard water, 500 ppm hardness) at30° C. and then transferred to a cylinder. The sample was topped up to250 ml with Water C and the cylinder was sealed. The sample wassufficiently agitated and then put in a water bath of 30° C. for 30mins. Then, 225 ml of suspension was taken out from the top and theresidual 25 ml at the bottom was transferred to a glass plate, dried andweighted. Degree of suspensibility was calculated as: (total weight ofthe granule−weight of the residue)/total weight of the granule. Thetotal weight of the granule is 2.5 g in this case.

Disintegration was measured by using the following procedure. 100 ml ofWater C (30° C. or 10° C.) were added into a cylinder, 1.0 g of the WDGgranules was transferred into the cylinder and sealed. Inverted thecylinder with a speed of 2 second/inversion until the granules werefully dispersed. The time for obtaining full dispersion was recorded.Results are shown in Table 5 below:

TABLE 5 EX9 EX10 CE8 CE9 EX11 CE10 EX12 CE11 Suspensibility 98.2% 98.6% >99% 99% 95% >99% 98.1%   98.2% Foaming  0  0   76 80  0  70  8   68(30° C., mm) Desintegration 28″ 28″   30″ 30″ 30″  32″ 30″   36″ (30°C.) Desintegration 52″ 48″ >120″ 60″ 52″  70″ 56″ >120″ (10° C.)

Results showed that the inventive surfactant composition (e.g. WettingAgent 1) led to satisfactory suspensibility. In addition, theformulations containing the inventive surfactant composition exhibitedreduced foaming compared to those containing short chain alkyl sulfatealone (e.g. Wetting Agent 2). Furthermore, the formulations containingthe inventive surfactant composition exhibited shorter disintegrationtime at low temperature. Such faster disintegration is particularlyadvantageous for solid agrochemical formulations, especially for use inlow temperature environment.

1. A surfactant composition comprising: (a) a sulfosuccinate basedcompound; and (b) a C₁₆-C₂₂ alkyl sulfate or an alkyl ether sulfatecontaining C₁₆-C₂₂ alkyl.
 2. The surfactant composition according toclaim 1, wherein the sulfosuccinate based compound is an agriculturallyacceptable salt of mono-ester of sulfosuccinic acid, an agriculturallyacceptable salt of di-ester of sulfosuccinic acid, each of which isoptionally alkoxylated, or a mixture thereof.
 3. The surfactantcomposition according to claim 1, wherein the sulfosuccinate basedcompound is according to the general formula (I):

wherein: R₁ and R₂, same or different, is

wherein R₃ is H, C₁-C₄ alkyl, alkenyl, hydroxyalkyl or hydroxyalkenyl;R₄ is C₁-C₂₂ alkyl, alkenyl, hydroxyalkyl or hydroxyalkenyl; n is 0 oran integer of 1 to 100; X⁺ is H or a cation.
 4. The surfactantcomposition according to claim 3, wherein in the general formula (I), R₁and R₂, same or different, is R₄ —O—, R₄ is C₁-C₂₂ alkyl, alkenyl,hydroxyalkyl or hydroxyalkenyl, X⁺ is H or a cation.
 5. The surfactantcomposition according to claim 1, wherein the C₁₆-C₂₂ alkyl sulfate isaccording to the general formula (II):R₅OSO₃ ⁻M⁺  (II) wherein R₅ is a C₁₆-C₂₂ alkyl or hydroxyalkyl group,either linear or branched, M⁺ is a cation.
 6. The surfactant compositionaccording to claim 1, wherein the alkyl ether sulfate containing C₁₆-C₂₂alkyl is represented by the general formula (III):R₆(AO)_(n)OSO₃ ⁻M⁺  (III) wherein R₆ is a C₁₆-C₂₂ alkyl or hydroxyalkylgroup, either linear or branched; AO is ethylene oxide (EO), propyleneoxide (PO) or mixture thereof; n represents degree of alkoxylation andis an integer of 1 to 100; M⁺ is a cation.
 7. The surfactant compositionaccording to claim 1, wherein the surfactant composition furthercomprises: (c) a C₁-C₁₄ alkyl sulfate or an alkyl ether sulfatecontaining C₁-C₁₄ alkyl.
 8. The surfactant composition according toclaim 7, wherein component (b) is at least 5 wt % of the total weight ofcomponents (b) and (c).
 9. The surfactant composition according to claim1, wherein the sulfosuccinate based compound is present in an amount offrom 1% to 50%, based on total weight of the surfactant composition. 10.The surfactant composition according to claim 1, wherein the C₁₆-C₂₂alkyl sulfate or the alkyl ether sulfate containing C₁₆-C₂₂ alkyl ispresent in an amount of from 1% to 90%, based on total weight of thesurfactant composition.
 11. A solid agrochemical composition comprisingan agriculturally active ingredient and the surfactant compositionaccording to claim
 1. 12. The solid agrochemical composition accordingto claim 11, wherein the agriculturally active ingredient is one or moreselected from a herbicide, an insecticide, a fungicide, an acaricide,and a rodenticide.
 13. The solid agrochemical composition according toclaim 11, wherein the solid agrochemical composition comprises saidsurfactant composition in an amount of from 0.1% to 10%, based on totalweight of the solid agrochemical composition.
 14. The solid agrochemicalcomposition according to claim 11, wherein the solid agrochemicalcomposition is a water dispersible granule (WDG), dry flowable (DF),wettable powder (WP), suspension concentrate (SC), suspoemulsion (SE),slow dispersing granule (GR) or a water soluble granule (WSG)formulation.
 15. A method for reducing or controlling the foaming of asolid agrochemical composition, comprising the step of adding to theagrochemical composition (a) a sulfosuccinate based compound; and (b) aC₁₆-C₂₂ alkyl sulfate or an alkyl ether sulfate containing C₁₆-C₂₂alkyl.